1. The very name "junk defense" isn't very inviting. Imagine if Coach Walberg referred to his AASAA offense as a "junk offense"...Calapari would have never listened to him when he pulled out the salt and pepper shakers at dinner.

2. I don't think many coaches know how to teach it or know its true effectiveness. When I was a varsity assistant at my alma mater my head coach was the master of the Diamond and 1. We worked on it EVERY day in practice. In fact, our defensive shell drills were out of the Diamond (not the traditional 44 or 33). Everybody knew what we did but it didn't really matter...we took away a lot of guys (that went on to have successful D1 and NBA careers) and we won A LOT of games.

Most of the time a team switches to a Box, Diamond or Triangle combination defense it done during a timeout and it only lasts 6-8 possessions.

Likewise, we practice it out of our match up zone overload drills [more offensive players than defensive] including 3 on 4 or 5 ... 4 on 5 or 6 ... I agree that you cannot prep it for one game or in a timeout ... we run 1-1-2 and chaser, triangle and 2 chasers and tandem and 3 chasers ... we also teach our zone players to block out chased players crashing ...